On some jobs, contractors rely on portable, on-site bending equipment - rather than a supply of factory-bent steel - to ensure they will have the exact quantities of bent rebar required. A variety of power and manual rebar benders is available - ranging from hand-held tools to wheel-mounted machines. Many benders are also equipped with cutting blades, allowing operators to shear rebar of various sizes.

The simplest rebar benders are manual tools that require the operator to provide the bending force. A manual bender is easily carried around the jobsite by one worker, most models weigh 70 pounds or less. Though manual benders are considerably less expensive than power models (costs of a manual bender with cutting blades range from $250 to $400), they have some limitations. Most models can only bend or cut one bar at a time, and some of these tools work best on lower-grade steel because it bends more easily. The tools also work best bending rebar 90 or 180 degrees.

Considerably heavier and more expensive than manual bending tools, power benders designed for on-site use range in weight from 180 to more that 800 pounds and cost between $3,500 and $5,500. Power benders allow contractors to make bends in Grade 60 rebar in seconds with the press of a button or a foot-pedal control. In addition to their fast bending speeds, power benders allow the operator to preset the bending angle, usually by adjusting a control dial. Once the angle is set, all bends will be identical until the control is adjusted again.